Rubinstein-Taybi syndrome (RTS) is a rare genetic disorder with characteristic physical anomalies. It is characterized by mental retardation, postnatal growth deficiency, microcephaly, specific facial characteristics, broad thumbs, and big toes. Behavioral problems are common with RTS; they include mental retardation, impulsivity, distractibility, instability of mood, stereotypes, poor coordination, atypical depression, and mania. To date, there is lack of literature on the presence of schizophrenia or non-affective psychosis with RTS. Here, we describe two cases where there is co-morbid psychosis with RTS. One case is diagnosed as paranoid schizophrenia and the other as psychosis possibly schizophrenia. Genetic analysis was not done due to unavailability. The possible etiological factors for the association of psychosis with RTS are discussed. Factors such as regulators of RNA polymerase II and hypoxia-inducible factor 1 alpha (HIF1A) may be some common etiological factors for the association of schizophrenia or non-affective psychosis and RTS. Schizophrenia / non-affective psychosis can be a comorbid psychiatric condition with RTS.